FDA approves Imaavy for generalized myasthenia gravis in patients aged 12 years and older

Key takeaways:

• Imaavy plus standard of care led to improvements at 24 weeks in basic functions such as chewing, swallowing and breathing.
• The monoclonal antibody had a similar tolerability profile for all age groups.

The FDA has approved a monoclonal antibody to treat individuals aged 12 years and older with generalized myasthenia gravis who are anti-acetylcholine receptor or anti-muscle-specific kinase antibody positive, according to the manufacturer.

In a press release, Johnson & Johnson said that Imaavy (nipocalimab-aahu) is the first and only neonatal fragment crystallizable blocker approved for this patient population.

“Adults and pediatric patients ages 12 and older living with [generalized myasthenia gravis] now have an additional treatment option designed to target one of the root causes of the disease with precision and predictability,” Bill Martin, PhD, global therapeutic area head, neuroscience, Johnson & Johnson Innovative Medicine, told Healio.

“Demonstrating durable improvements in key functional outcomes — such as enhanced ability to eat and reduced shortness of breath—with a consistent safety profile across both pediatric and adult populations, Imaavy marks a new therapeutic option,” Martin said.

Approval was supported by data from the ongoing phase 3, double-blind, placebo-controlled Vivacity-MG3 study, which investigated Imaavy in 199 patients.

Enrollees were randomly assigned on a 1:1 basis to receive either a loading dose of 30 mg/kg IV nipocalimab followed by 15 mg/kg every 2 weeks plus current standard of care (SOC) or placebo plus current SOC.

The study’s primary efficacy endpoint was a comparison of the mean change from baseline to weeks 22, 23 and 24 between treatment groups in the Myasthenia Gravis Activities of Daily Living (MG-ADL) total score, with secondary endpoints including change in Quantitative Myasthenia Gravis (QMG) score.

According to data cited in the release, Imaavy plus SOC improved MG-ADL scores up to 24 weeks compared with placebo plus SOC, indicating greater control over basic functions such as chewing, swallowing, speaking and breathing. These improvements were maintained up to 20 months of follow-up in the study’s ongoing open-label extension.

Data further showed that treatment with Imaavy also led to “rapid and sustained reduction” in autoantibody levels by up to 75% from initial dosing, which continued throughout 24 weeks, per the release.

Additional data from the ongoing phase 2/3 Vibrance clinical trial involving adolescents aged 12 to 17 years who were anti-AChR and anti-MuSK antibody positive found Imaavy plus SOC met a primary endpoint with a 69% reduction in total serum IgG over 24 weeks, as well as secondary endpoints of improvements in MG-ADL and QMG scores.

The drug also demonstrated a similar safety profile across both aforementioned studies, with similar tolerability profiles across all age groups, Johnson & Johnson reported in the release.